The 2JZ engine is an iconic powerplant. To qualify that statement, think about this – everyone knows what a 2JZ engine is. Whether you’re an import or domestic fan; a drag racer, drifter, or street car enthusiast; whether you’re into small four cylinders or big V8s – you’ve at least heard of Toyota’s powerhouse inline-six-cylinder engine.
Steph Papadakis of Papadakis Racing put together a video of him tearing town one of the 3.0-liter Japanese mills in preparation for a big-power build. Of course, it’s Steph Papadakis, so it’s not just going to be a montage of spinning wrenches and removing bolts. But rather, Papadakis dives into the details of what makes this engine so popular, and so receptive to aftermarket modification, along the way.
While the 2JZ is largely known for powering the Toyota Supra, the fact is, over the years it has powered a variety of JDM and USDM vehicles in both naturally aspirated and turbocharged variants. This particular engine was brought over from Japan and was originally a twin-turbo variant out of an Aristo, so it has variable valve timing.
Papadakis starts the teardown by pulling the manifolds off, followed by the accessories. He also points out the unusual ignition setup, in which three cylinders have a coil-on-plug setup, while the other three have ignition wires leading off of those three coils.
After pulling off the valvecovers, Papadakis gives a quick explanation of how the engine’s dual overhead cam valvetrain operates, before walking us through the proper sequence to remove the variable timing-equipped intake cam sprocket. He also warns of the potential of breaking a camshaft if the engine isn’t at Top Dead Center and the cam caps aren’t loosened in the proper outside-inward sequence.
Once the head has been removed, Papadakis dives into what makes the 2JZ such an awesome engine. As simple as it may seem, the fact that from the factory, the 2JZ has a closed-deck beefy iron block is the basis for most of the engine’s power-holding ability. Another thing that seems like a no-brainer today (but was cutting edge tech from an OEM 25-plus years ago) is that Toyota used a three-layer Multi-Layered Steel gasket, which allowed the factory engine to hold significant boost.
As he continues disassembly of the bottom end, Papadakis talks about another component that lends strength to the 2JZ, and that is the OEM Block girdle. Instead of running a full length oil pan like many engines, there is a cast-iron girdle attached to the bottom end with a small pan the size of the sump area on a domestic V8. The girdle adds rigidity and strength to the engine in an area that usually only has a stamped steel (or fabricated aluminum) oil pan.
As the short block comes apart, Papadakis points out that the OEM crankshaft is a beefy forged unit, and that the main bearings are quite wide, and offer a lot of support, along with a significant amount of thrust bearing surface. Coupled with the large amount of internal webbing in the block, it’s not uncommon to hear of 700-800 horsepower on the stock bottom end without much trouble.
Before anyone mentions “stock bottom end” LS engines, keep in mind, while this was happening with the 2JZ, the Mustang was powered by a pushrod 302 that was on borrowed time above 500 horsepower, and the Camaro was running a Gen II LT1 which wasn’t a whole lot better when comparing stock short-blocks. So while crazy numbers from OEM components is a common occurrence these days, 25 years ago, it was a far more impressive feat, and part of the reason the 2JZ has earned it’s reputation for being an incredibly impressive engine.